Drumless boiler



Nov. 15, 1932. e. LASKER 1,887,854

DRUMLESS BOILER Filed July 24. 1930 5 Sheets-Sheet 1 Nov 15, 1932. LAsKER 1,887,854

DRUMLESS BOILER,

Filed July 24. 1950 5 Sheets-Sheet, 2

Nov.

Filed July 24. 1930 (7&3.

5 Sheets-Sheet 5 Patented Nov. 15, 1932 PATENT. OFFICE- GI'DBGB LASKER, CHICAGO, ILLINOIS DBUIDZESS BOILER Application fled m 24,

The invention relates to boilers and more particularly it relates to boilers subjected to rapidly changing loads orpower requirements.

In boilers operated at critical temperature and pressure substantially all of the liquid in the upper portion of the boilers is increased in volume almost three fold, since the weight of water is about 62.5 pounds per uare mafoot and the weight of the emulsified hquid at the critical point is approximately 21.

pounds per square foot.

Boilers as at present constructed comprise one or more drums or cylinders into the bottom half of which a plurality of tubes directly discharge emulsified liquid and steam which has been generated in the tubes.

When operating such boilers at capacity or above, the drums tend to fill with a mixture of the emulsified liquid and steam and the liquid contained in the boiler is in violent ebullition by reason of such discharge therethrough, therebymaking it impossible to determine the true water level.

Inasmuch as boilers are frequently unavoidably operated above their rated ca acity and such operations are accompanie by a corresponding increase in the volume of emulsified water, it is found necessary in such boilers to have the normal water line well within the boiler in order that such expansion of the liquid may occur without requiring that a portion of theemulsified liquid be drawn 0a to prevent the water flowing into the steam line which is undesirable for obvious reasons.

In practice boilers are sometimes operated at double their rated capacity in meeting load requirements, and experiments show that at least 90 inchesin length of the upper ends of the tubes adjacent the drums into which they discharge are filled with steam when the boiler is so operating. When the load re- 'quirements are diminished the large volume 4.5 'of emulsified liquid suddenly returns to its 1980. Serial Io. 470,859

normal li uid. condition and the water line immediate y drops to a level well within that portion of the boiler exposed to direct contact with the gases of combustion.

The upper ends of the tubes above the water line are thereby left in a state of complete or partial dryness. This rapid drop in the water line thereb not only exposes the upper ends of the oiler tubes to danger of so-called burnin but also to excessive strains due to sud en changes in tem rature and pressure conditions. This liability to destruction or deterioration requires that such boilers have constant skilled supervision to avoid disaster and with such supervision it is necessary to fr uently overhaul and repair such boilers. T e deteriora tion and danger of destruction as a result of changing load conditions are greater in large power installations where gas, oil or was dercd coal are used as fuel, since a arge furnace volume is necessarily provided, which will be slower in cooling and expose the empty boiler portions to burning for a longer period than would a smaller furnace. 10

The invention contemplates a novel boiler construction wherein the boiler roper is connected with a drum positione well above the boiler proper. The capacity of the drum is predetermined in accordance with the ca- 76 pacity of the boiler and it functions in a dual capacity as a receiver for the steam and emulsified water as it is discharged from the boiler and in providing a reservoir of water, the surface of which is the normal water line so of the boiler. The water contained therein provides a static head pressure for all parts of the boiler and an object of the invention is the provision of an improved boiler construction equally adapted for large and for small in- 0 stallations and which maintains all portions. of the boiler under a static head, thereby avoiding the possibility of substantial vanations in the water line corresponding to different load conditions.

above the drum and discharge the steam and.

emulsified water downwardly through the up per wall of the drum. The water is separated from the steam by gravity and falls to the surface of the water body in the drum.

Since there is no discharge directly from the boiler through the water contained in the drum the elevation of the water in the drum is substantially stationary and the water sufficiently quiescent to permit accurate readings of the water column. i

A still further object is the provision of an improved boiler construction. wherein there are no drums or tanks exposed to furnace gases thereby permitting the heated gases to come into contact with a larger number of tubes than is the case where tanks or drums form a portion of the boiler construction.

A still further object of the invention is to provide a novel form of roof and header construction providing novel interconnecting means for recirculating the water.

Many other objects and advantages of the construction herein shown and described will be obvious to those skilled in the art from the disclosure herein given.

To this end my invention consists in the novel construction, arrangement and combination of parts herein shown and described and more particularly pointed out in the claims.

Referring now to the drawings wherein like numerals indicate like or corresponding parts,

Fig. 1 is a transverse vertical sectional view through a boiler embodying the principles of my invention;

Fig. 2 is a view along the line 2-2 of Fig. 1;

Fig. 3 is a view along the line 3-3 of Fig. 1

Fig. 4 is a partial plan view of the boiler;

Fig. 5 is a view along the line 5-5 of Fig. 6 is a view similar to Fig. 2;

Fig. 7 is a view along the line 7-7 of Fig. 1; and

Fig. 8 is a view illustrating certain specific features of the invention.

Referring now more particularly to the drawings, the numeral 10 generally designates a furnace in which are mountedheaders, pipes, tubes, etc. comprising the boiler proper. The furnace comprises a front wall 11, a rear wall 12, side walls 13, a roof 14, a partition wall 15 and a floor 9. The walls and floor of the furnace may be of any desired construction and insulation, the details of which are not herein further described inasmuch as they constitute no part of the invention.

The construction shown is adapted to use either powdered coal, oil or gas as fuel which is delivered into a combustion chamber 17 through a fuel inlet 16. The gases of combustion ascend and come into contact with the roof 14, the space immediately adjacent the roof forming an incandescent heat zone. The 7 gases pass from the radiant heat zone downwardly between the partition wall 15 and the rear wall 12 and make their exit through the outlet 18. The side walls 13 of the furnace are lined with a plurality of vertically extending tubes 21 which form a water cooled wall forthe furnace. The tubes 21 are connected at their lower and upper ends with headers 22 and 23, respectively. The rear end of the headers 22 are connected with a standpipe 41 positioned in the rear of the furnace. The front ends of the headers 22 project through the front wall 11 of the furnace and are connected with a. horizontally extending header 26 by vertical pipes 25.

A plural ty of vertically extending tubes 27 connect the header 26 with a header 28 positioned in the front upper'portion of the furnace. The tubes 27 form a water cooled wall bounding the radiant heat zone. The ends of the header 28 are connected with a relatively large longitudinally extending header 24 by the headers 23.

' A pair of headers 30 are positioned underneath the corresponding headers 23 and connected therewith by a plurality of tubes 29 as best shown in Fig. 3. The tubes 21 discharge a mixture of steam and emulsified water into the headers 23. Similarly the header 28 delivers such a mixture to the 105 headers 23 as was discharged therein by the front wall tubes 27. The water contained in the headers 23 flows by gravity through the tubes 29 into the underlying headers 30 and the steampasses into the relatively large 110 header 24 from which it is discharged in a The tubes 31 are arranged to alternately connect the headers 30 with the oppositely positioned headers 23, the tubes 31 thereby forming a water cooled wall or lining for the roof of the furnace. The connection of a header 23 with the header 30 andqa header 30 with the oppositely positioned header 23 provides a means for separating the steam generated by the front wall tubes 27 and side wall tubes 21 from the water and causing the water to 126 recirculateand pass through the tubes 31, from whichit is again discharged in the form of steam'and water into headers 23 and recirculated until it is all converted into steam: The headers 23 are connected at the 130 'rear of the furnace by a pipe 20'. The inclinae tion of the tubes 31 can be any deslred amount, depending upon the capacity and size of the installation. 5 The end walls of the rear portion of the upper radiant heat zone are lined with a plurality of vertically extending tubes 35 connected at their upper ends with the headers 23 and at their lower ends with headers 34. The space between the partition wall 15 and the rear wall 12 of the furnace,through which the gases from the radiant heat zone are directed downwardly, commonly called the dark zone is filled with a plurality of rows of transverse substantially horizontal tubes 39.

The end Walls of the space, known as the dark zone, are lined with a plurality of horizont ally extending headers 37 and 38 in whlch the tubes 39 terminate.

The oppositelypositioned headers 37 and 38 lie in-the same horizontal plane and the tubes 39 are inclined slightly to the horizontal, the inclination being such that the tubes terminating in the same headers 37 and 38 connect at their other ends with the headers immediately above and below the corresponding header in the opposite-end wall.

In Fig. 6 is shown a modified structure wherein tubes 59 are substituted fon tubes 39 and the headers 37 and 38 of one end wall are so arranged that horizontal planes, through their axes, pass between the corresponding headers of the opposite end wall. By this arrangement, the tubes 59 do not 1n- -5 tersect as do the tubes 39-but extend in substantially equally spaced parallel relation through the greater portion of their. lengths. Two rows of tubes 59 are connected with each other, the upper row being connected with the bottom portion of an opposite header and the lower row being connected with the upper portion of a header lying immediately underneath the last mentioned header.

The headers 37 and 38 and the tubes 39 are supplied with water through an inlet pipe 40, the water circulating upwardly and back and forth through the inclined tubes and the'vertical row of headers. The water as it rises through the tubes 39 and the headers 37 and 38 meets the downward flow of gases, the descending gases parting with their heat and the ascending water absorbing the same. The upper rows of tubes 39 connect with the head ers 34 and the water after passing through the dark zone is discharged from the headers 34 into the headers '23 through the tubes 35. The headers 38 are similar to the headers 37, differing therefrom in length and by being extended rearwardly. These extended headers 38 are tapped on their upper surfaces by bleeder or discharge pipes 64, connecting the headers with the upper portion of a drum 46. The pipes 64 provide means for discharging emulsion'and steamirom the dark zone 65 as rapidly as it is generated therein.

pressure.

forming water cooled walls of the furnace and also the tubes 39, interspersed throughout the dark zone back of the partition wall 15, are connected directly or indirectly with the large header 24 in such a way that all of the steam and the emulsion generated by the boiler is discharged into the header 24 except a relatively small quantity which is carried through the pipes 64 into the drum 46.

The drum 46 is positioned at any convenient elevation above the boiler proper in accordance with the space requirements, in order that a static pressure head may be maintained thereby throughout the boiler proper. All of the boiler system and a portion of the drum 46 are filled with water so that the boiler water line passes throu h the drum. The drum-46 is provided to per orm the dual function of a steam drum and a reservoir for water providing a predetermined static head The drum 46 is supported bya pair of transverse I-beams 48 which in turn rest upon a pair of longitudinally extending I -beams 47, the supporting structure of I- beams being carried by columns 49. The drum 46 is directly connected with the boiler system by a pair of pipes 51 which open at their upper end into the bottom of the drum and are connected with the headers 30 through pipes 36, forming apart of the boiler system. The headers 30 are supplied with water only from the headers 23 by'means of the vertical tubes 29, as already described. The arrangement of the headers 23 and 30 and the connecting tubes 29 and 31 is such that no steam or mixture of emulsion and steam is discharged into the headers 30 and as a result there is no 7 ossibility of steam or emulsion entering the bottom of the drum 46 through the pipes 36 and 51.

The upper end of the standpipe 41 extends above the drum 46 and the water level therein remains at substantially the same eleva tion as the water level in the drum. The

space in the upper end of the standpipe 41 provides an accumulator for the steam and emulsion generated in the standpipe and also provides a receiving chamber for the steam and emulsified water conveyed by the pipe 52 from the header 24. The pipe 52 discharges downwardly into the standpipe 41 and the. water is separated from the steam by gravity. The steam in the upper end of the standpipe flows through a pipe 54 and is discharged into the upper portion of the drum 46 or flows to a super heater as hereinafter described. A screen 53 positioned adjacent the open end of,the pipe 52 prevents any water from flowing to the drum 46 through the pipe 54.

A pair of pipes 55 which are branches of the pipe 54 are provided to connect the drum 46 and the upper end of the standpipe wlth a super heater. The super heater may take any desired form and is shown as comprising a header into the ends of which the pipes 55 discharge, a second header 61 connected with the header 60 by a plurality of tubes 63 and a third header 62 also connected with the header 61 by a plurality of U shaped tubes 63.

All of the emulsified liquid and steam generated by the boiler reaches the upper end of the standpipe 41 and the upper portion of the drum 46, the important feature being that none of the mixture is discharged into the drum upwardly through the liquid contained therein as is the practice in boilers as at present constructed. The drum 46 is not a part of the boiler system but serves as a reservoir for steam and its water contents provide a static'head on the boiler system proper. The rapidity of circulation through the boiler depends upon the elevation of the drum 46, the higher the drum, the more rapid being the circulation. It is obvious that under the static head pressure provided by the drum 46, the boilerwill never reach the critical temperature and that the volume of the mixture of emulsion and steam contained in the header 24, the pipes 52 and the upper end of the standpipe 41 will never be suflicient to cause a perceptible lowering of the water level in the drum 46 and that there is no possibility of any portion of the boiler system proper being exposed to burning or excessive strains which have to be contended with in boilers operated at critical temperatures as at present constructed. The provision of a vertical standpipe as a portion of the boiler system with its upper end projecting above the boiler a substantial distance to provide a chamber through which all of the steam must pass in reaching the upper portion of the static head drum is also an important and novel feature of the invention.

Having thus described my invention, it is obvious that various immaterial modifications may be made in the same without departing from the spirit of my invention; hence, I do not wish to be understood as limiting myself to the exact form, construction, arrangement and combination of parts herein shown and described or uses mentioned.

What I claim as new and desire to secure by Letters Patent is:

- 1. A boiler comprising a plurality of interconnected tubes and headers, a static head drum positioned at an elevation above the boiler, a standpipe pro'ecting above said boiler and drum, a con uit connecting the boiler and standpipe, said conduit being at a lower elevation than said drum, a conduit connecting the upper portion of said boiler with the upper end of said standpipe, a conduit connecting the upper end of said standpipe with the upper portion of said drum,

and a conduit connecting the lower portion with the upper end of said standpipe, a conduit connecting the upper end of said standpipe with the upper portion of said drum, a conduit connecting the lower portion of said drum with-the upper portion of the boiler, and a plurality of pipes connecting the upper portion of said drum with a plurality of points in the boiler intermediate its upper and lower portions.

3. In combination a furnace having a radiant heat zone through which gases travel in one direction and a dark zone through which said gases travel in the opposite direction, a boiler system comprising a plurality of interconnected tubes and headers, a portion of said tubes and headers lining the walls bounding said radiant heat zone and a portion of said tubes and headers positioned in said dark zone, a static head drum positioned above said boiler system, a vertical standpipe projecting above said boiler system and drum, a conduit connecting the boiler system with the lower portion of said standpipe, a conduit connecting the upper portion of said boiler system with the upper end of said standpipe, a conduit connecting the upper end of said standpipe with the upper portion of said drum, and a conduit connecting the lower portion of said drum with said boiler.

4. In combination 'a furnace having a radiant heat zone through which gases travel in one direction and a dark zone through which said gases travel in the opposite direction, a boiler system comprising a plurality of interconnected tubes and headers, a portion of said tubes and headers lining the walls bounding said radiant heat zone and a portion of said tubes and headers positioned in said dark zone, a static head drum positioned above said boiler system, avertical standpipe projecting above said boiler system and drum, a conduit connecting the boiler system with the lower portion of said standpipe, a conduit connecting the upper portion of said boiler system with .the upper end portion of said drum, a conduit connecting the lower portion of the drum with the upper portion of the boiler system, and a plurality of pipes connecting the top of said drum With that portion of the boiler system positioned in said dark zone, the points of connection of said pipes with said boiler system being at diiferent elevations.

In witness whereof, I hereunto subscribe my name this 16th day of July, A. D. 1930.

' GEORGE LASKER. 

